Oxygen isotope and palaeomagnetic stratigraphy of Equatorial Pacific core V28-238: Oxygen isotope temperatures and ice volumes on a 105 year and 106 year scale☆
TL;DR: The core Vema 28-238 as discussed by the authors preserves an excellent oxygen isotope and magnetic stratigraphy and is shown to contain undisturbed sediments deposited continuously through the past 870,000 yr.
About: This article is published in Quaternary Research.The article was published on 1973-06-01. It has received 2515 citations till now. The article focuses on the topics: Oxygen isotope ratio cycle & Northern Hemisphere.
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TL;DR: It is concluded that changes in the earth's orbital geometry are the fundamental cause of the succession of Quaternary ice ages and a model of future climate based on the observed orbital-climate relationships, but ignoring anthropogenic effects, predicts that the long-term trend over the next sevem thousand years is toward extensive Northern Hemisphere glaciation.
Abstract: 1) Three indices of global climate have been monitored in the record of the past 450,000 years in Southern Hemisphere ocean-floor sediments. 2) Over the frequency range 10(-4) to 10(-5) cycle per year, climatic variance of these records is concentrated in three discrete spectral peaks at periods of 23,000, 42,000, and approximately 100,000 years. These peaks correspond to the dominant periods of the earth's solar orbit, and contain respectively about 10, 25, and 50 percent of the climatic variance. 3) The 42,000-year climatic component has the same period as variations in the obliquity of the earth's axis and retains a constant phase relationship with it. 4) The 23,000-year portion of the variance displays the same periods (about 23,000 and 19,000 years) as the quasi-periodic precession index. 5) The dominant, 100,000-year climatic [See table in the PDF file] component has an average period close to, and is in phase with, orbital eccentricity. Unlike the correlations between climate and the higher-frequency orbital variations (which can be explained on the assumption that the climate system responds linearly to orbital forcing), an explanation of the correlation between climate and eccentricity probably requires an assumption of nonlinearity. 6) It is concluded that changes in the earth's orbital geometry are the fundamental cause of the succession of Quaternary ice ages. 7) A model of future climate based on the observed orbital-climate relationships, but ignoring anthropogenic effects, predicts that the long-term trend over the next sevem thousand years is toward extensive Northern Hemisphere glaciation.
3,408 citations
TL;DR: Using the concept of "orbital tuning", a continuous, high-resolution deep-sea chronostratigraphy has been developed spanning the last 300,000 yr as mentioned in this paper.
3,256 citations
Cites background from "Oxygen isotope and palaeomagnetic s..."
...The exact climatic significance of these parameters, or “paleoclimatic indicators,” is uncertain (Shackleton 1977; Broecker, 1982; Shackleton and Opdyke, 1973; Hays et al., 1976; Imbrie and Kipp, 1971; Berger, 1973; Dunn, 1982; Moore et al., 1982)....
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TL;DR: In this article, the authors re-examine the data and conclude that the temperature of the abyssal ocean has been an actively varying component of the climate system, and that there has been a discrepancy between the ice volume record that these records imply and that derived from the altitude of dated coral terraces around the world.
Abstract: From the time that detailed oxygen isotope records derived from foraminifera living in the constant-temperature environment of the abyssal ocean became available, there has been a discrepancy between the ice volume record that these records imply, and that derived from the altitude of dated coral terraces around the world. Here, we re-examine the data and conclude that the temperature of the abyssal ocean has been an actively varying component of the climate system.
1,621 citations
TL;DR: In this paper, a modified version of the timescale proposed by Imbrieet et al. for the ODP Site 677 has been proposed, based on the precession signal in the record from ODP site 677 that provides the basis for the revised timescale.
Abstract: Ocean Drilling Program (ODP) Site 677 provided excellent material for high resolution stable isotope analysis of both benthonic and planktonic foraminifera through the entire Pleistocene and upper Pliocene. The oxygen isotope record is readily correlated with the SPECMAP stack (Imbrieet al.1984) and with the record from DSDP 607 (Ruddimanet al.1986) but a significantly better match with orbital models is obtained by departing from the timescale proposed by these authors below Stage 16 (620 000 years). It is the stronger contribution from the precession signal in the record from ODP Site 677 that provides the basis for the revised timescale. Our proposed modification to the timescale would imply that the currently adopted radiometric dates for the Matuyama–Brunhes boundary, the Jaramillo and Olduvai Subchrons and the Gauss–Matuyama boundary underestimate their true astronomical ages by between 5 and 7%.
1,599 citations
01 Jan 1975
TL;DR: An oxygen and carbon isotopic history based on analyses of benthonic and planktonic foraminifera in three overlapping subantarctic sections is presented for the last 55 m.y. as mentioned in this paper.
Abstract: An oxygen and carbon isotopic history based on analyses of benthonic and planktonic foraminifera in three overlapping subantarctic sections is presented for the last 55 m.y. with a sampling interval ofless than 1 m.y. Surface temperature at Site 277, on the Campbell Plateau, was about 19°C in the early Eocene, about 13°C in the middle Eocene, about 11°C in the late Eocene, and about 7°C in the Oligocene. Declines in temperature appear to have been rather rapid and are separated by episodes of relative temperature stability. Bottom temperature at Site 277 was about 1°C below surface temperature in the Paleocene and about 2°C below surface temperature in the Oligocene. Site 279, on the Macquarie Ridge, records an early Miocene warming of over 2°C followed by a cooling and a second similar temperature rise in the middle Miocene. Bottom temperature at this somewhat deeper site was about 3°C below surface temperature and was probably as low as 4°C during part of the early Miocene. Comparisons between Sites 277 and 279 suggest that from the early Oligocene temperatures of deep water were low like the present day, implying that the mean annual temperature in high southern latitudes was near freezing by the beginning of the Oligocene (but certainly no earlier). From this time glaciers would have descended to sea level, and there would have been sea-ice production. If an ice sheet were present, it could not have been more than a small fraction of its present-day size. Site 281, on the South Tasman Rise, extends the record into the middle and late Miocene during which time the major East Antarctic ice sheet accumulated. A significant rise in surface temperature during the late Miocene did not cause the melting of this ice sheet, demonstrating that by this time it had already achieved its present invulnerability to climatic change. Since temperatures during much of the Miocene were significantly above any Pleistocene values, it is extremely unlikely that any climatic change in the geologically near future will significantly affect the stability of the East Antarctic ice sheet.
1,565 citations
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2,181 citations
TL;DR: The relationship between temperature and O(18) content relative to that for a Cretaceous belemnite of the Pee Dee formation previously reported (Epstein, Buchsbaum, Lowenstam, and Urey, 1951) has been re-determined using modified procedures for removing organic matter from shells, and is found to be 16.5 - 4.3 δ + 0.14 δ^2
Abstract: The relationship between temperature and O^(18) content relative to that for a Cretaceous belemnite of the Pee Dee formation previously reported (Epstein, Buchsbaum, Lowenstam, and Urey, 1951) has been re-determined using modified procedures for removing organic matter from shells, and is found to be
t(°C) = 16.5 - 4.3δ + 0.14δ^2
where δ is the difference in per mil of the O^(18) to O^(16) ratio between the sample and reference gas. The new relationship agrees with that determined by McCrea (1950) for inorganically precipitated calcium carbonate. Carbonate-carbon dioxide exchange experiments were done to determine the direct and indirect effects of organic matter in the shell on the mass spectrometer analyses.
2,109 citations
TL;DR: In this article, a detailed curve of ice volume versus time is needed in order to test the validity of the hypothesis that changes in the earth's orbital parameters are the cause of oscillations in Pleistocene climate.
Abstract: A detailed curve of ice volume versus time is needed in order to test the validity of the hypothesis that changes in the earth's orbital parameters are the cause of oscillations in Pleistocene climate. Although absolute ages available for glacial moraines and raised coral reefs provide a number of key points, they by no means allow a continuous curve to be drawn. Those points that exist, however, are entirely consistent with the hypothesis that the O18/O16 curves from deep-sea cores provide good approximations to the ice volume record. If so, then the primary glacial cycle must be sawtoothed in character; gradual glacial buildups over periods averaging 90,000 years in length are terminated by deglaciations completed in less than one tenth this time. Modulating this primary cycle are secondary oscillations. Those recognized during glacial growth phases average 20,000 years in length and those during the retreats about one thousand years in length. When the ice volume curve obtained in this way is compared with the summer insolation curve for the northern hemisphere, it is seen that the rapid deglaciations occur during times of unusually great seasonal contrast and that the secondary cycles modulating the glacial buildups closely parallel the insolation variations. Although these findings provide convincing evidence for the influence of orbital changes on climate, the cause of the primary sawtoothed cycle is still an open question. In conjunction with this study, we have determined the O18/O16 record for Caribbean core V12-122 and find it to be compatible with those given by Emiliani for cores P6304-8 and P6304-9. Our dating of this core by Pa231-Th230 and by magnetic reversals, however, strongly suggests that the absolute time scale adopted by Emiliani for deep-sea cores must be increased by 25%.
763 citations
TL;DR: Oxygen isotope analyses of foraminiferal tests in deep-sea cores have been interpreted as showing that the temperature of seawater in the Caribbean and equatorial Atlantic varied by as much as 6°C during glacial cycles as mentioned in this paper.
Abstract: Oxygen isotope analyses of foraminiferal tests in deep-sea cores have been interpreted as showing that the temperature of seawater in the Caribbean and equatorial Atlantic varied by as much as 6° C during glacial cycles. This evidence has now been reinterpreted, and changes in oxygen isotope composition are now said to correspond with the extraction of large amounts of water from the oceans during glacial periods and the recirculation of this water during periods when glaciers were at their present levels.
716 citations
TL;DR: In this article, a relationship between temperature and relative O 18 abundance in calcium carbonate in marine shells has been determined, where the relative abundance of the water in which the shell grew is known, and the temperature can be determined to an accuracy of ± 1.0°C.
Abstract: A relationship between temperature and relative O 18 abundance in calcium carbonate in marine shells has been determined. If the relative O 18 abundance of the water in which the shell grew is known, the temperature can be determined to an accuracy of ±1.0°C. The relative O 18 contents of marine waters increase with salinity and, in the case of surface marine waters, with salinity and temperature.
558 citations